By Sheila Pratt, Edmonton Journal
EDMONTON - On the last evening of October, a wall of water and sludge poured out of the Obed coal mine containment pond, uprooting trees and cutting down vegetation in a swath 20 metres wide on either side of the Apetowun trout stream.
The coal slurry rose over the creek banks, spreading contaminated sediment into the forest as far as 10 kilometres downstream on the creek, which eventually joins the Athabasca River. A layer of sediment about 50 centimetres thick lies under the snow in some places.
The extent of the damage in the early moments of the Oct. 31 spill emerged for the first time Monday at a University of Alberta forum attended by First Nations leaders, Alberta Environment officials and Obed mine owner Sherritt International.
The Apetowun and Plante creeks were essentially wiped out by the 670-million-litre spill, and there are serious concerns about damage to fish populations, the forum heard.
“It was a pretty substantial wall of water,” said Alberta Environment spokesman Colin Cooke, who displayed photographs of the upper reaches of the stream.
Due to snow cover, it is not possible to determine the exact area where the black sediment was deposited on the landscape, said Cooke. But it will be important to monitor how much of it ends up in the Athabasca River in the spring melt, he said.
The spill launched a plume of slurry, containing fine coal particles, clay and heavy metals, into the river, which gradually moved downstream through November.
While contamination in the river did not exceed drinking water guidelines, it did in some places exceed levels necessary to protect aquatic life and for irrigation, Cooke said.
U of A water scientist Bill Donahue said the fact that the sediment has settled also means there’s pollution along the river bed: “The concentration of contaminants has increased along the length of river.”
The U of A’s Mark Poesch, who studies freshwater fish, predicted spawning in these streams will be damaged for years.
“It’s too early to estimate, but there is likely to be significant damage to fish population,” he said.
No one from the federal Fisheries Department, which is responsible for fish populations, attended the forum Monday.
Chief Allan Adam, of the Athabascan Chipewyan First Nation on Lake Athabasca, told the forum that First Nations end up dealing with the long-terms effects of the spill.
“If this river flowed south into some major cities, you’d have the whole country in an uproar,” said Adam.
He also raised the question of much larger and old tailings ponds at the open-pit mines in the oilsands.
“We’ve got major tailing ponds in our area and what are the chances they will breach? They are 50 years old ... We’ve been assured for years this (spill) would not happen, but it did.”
Sean McCaughan, Sherritt’s senior vice-president for coal, was asked at the forum if the company ever considered offering a public apology.
“A great question,” he said, later adding, “We are sorry it happened.”
He said the company is “determined to get to the bottom of it.”
Sherritt will release its water sampling results, likely by the end of this week, he said.